Often called a kinsman-redeemer, this person was responsible for protecting members of the extended family-a big brother, so to speak.
If a woman’s husband died, a relative- – the family redeemer- was obligated to take over the husband’s duties and care for his wife and children. He would “redeem,” or buy back any property in order to provide for them. Boaz was not the first relative in line. So he secured the permission of the first man in that line, with public witnesses, and then filled the role, encouraged to do so by Ruth’s own expression of interest in becoming his wife.
Ruth 3:12 – 12 And now it is true that I am thy near kinsman: howbeit there is a kinsman nearer than I.